School-seat hinge



{No.Model.)

J. W. FISHER. SQHOL SEAT HINGE- No. 518,988 Patented May 1,'1894.

i Mirna 'i STATES' JAMES WILLIAM nisnna, on PIQUA, onto.

SCHOOL-SEAT HINGE.

SPECIFICATION forming part of Letters Patent No. 518,988, dated May 1, 1894.

Application tiled December 18, 1893x Serial No. 493,937. (No model.)

, To all whom it may concern: y v Beit known that I, JAMES WILLIAM FISHER, a citizen of the United States, residing at Piqua, in the county of Miami and State of,V 5 Ohio, have invented certain new and useful Improvements in. School-Seat Hinges; and I do hereby declare the followingto be a full,

clear,` and exact description of the invention,

such as will enable others skilled in the art to which it appertains to make and use the same. v j

My invention relates to improvements in the construction of joints adapted. for school seats, and more especially t-o that class wherein the friction of the bearings isincreased as the seat arm reaches near its limit of travel, in order to obviate `thenoise incident to the banging due to the sudden stoppage of said arm, and to case the strain on the parts as isr well known.

rIhe objectsof my invention areto distribute equally the friction over bearing surfaces of the members of the joint, to simplify the construction, to make the parts' easily attachable and detachable, and to improve the construction generally.

The objects of my invention are accomplished by the features of construction and arrangements of devices, as hereinafter described and claimed, reference being made to the accompanying drawings, in which- Figure 1 is aside elevation of a school desk showing a seat connected' thereto by my improved ball-disk joint. Fig. 2 is a side yview of the pivoted or rocking member of the balldisk joint which is connected to the seat-arm.

Fig. 3 is a similar View of the'opposite side of f said member. Fig. 4 is an inside elevation of the socket which is connected to the deskv standard. Fig. 5is an inside elevation of the cap-piece with a iiat spring friction plate seated therein, and the friction disk removed. Fig. 6 is a sectionthrough the joint on the line .fr-a; Fig. l. Fig. 7 is a side elevation of the friction4disk looking in the direction` of the arrow Fig. 6.

Like reference letters refer to like parts in the several figuresf A, represents a frame of. the desk and B a standard to which the seat arm C isconnected by means of a ball-diskjointD. The ball disk joint or hinge D is composed of asocket is a circular metal plate which has a central concave depression or .recess e forthe' reception of an approximately hemi-spherical protuberance on the knuckle or member F. Surrounding the depression e is a flat circular bearing surface e', for the member F. The socket piece E is provided with a segmental recess or slot e2, for thereception of a similarly shaped lug on the knuckle or 'member F, as hereinafter described. Partially surrounding the flat circular bearing surface e',

is a segmental ange or rim e3, which forms a peripheral bearing surface for the knuckle or member F. The segmental rim eS terminates in two shoulders e4, e5, which contact with similar shoulders on the knuckle F when the yseat is raised orlowered. The socket piece E,

or the standard on which said piece is secured is provided with a recess e, for the reception of a locking lug on the cap piece as hereinafter described.. The knuckle or ball-like member F which [its and turns in the socket` piece E, is provided on one side (as shown in Fig. 2) with a hemispherical like protuberance f, a dat circular bearing surfacef, a segmental lug f2,'and a segmental rim or ange f3, which terminates in the shoulders f4 and 5. The member F on its opposite side (as shown in Fig. 3,) is provided with a Iiat circular bearing surface f6 and a protuberance f7, similar tothe part f. The heini-spherical protuberance f7'is provided with a swell or bulging portion fs, for the purpose hereinafter stated. `The cap piece G has on its rim a flat circular bearing surface g, on which the cir cular ange f6 of the knuckle or ball member of the joint bears. On the inner side of the rim of the cap and extending down into the crown thereof are two square cut away portions or notches g', g. These notches are located opposite to each other and are for the purpose of receiving projecting lugson the' IOO of the cap is provided with a slight depression or recess (as shown in Figs. 5 and 6) for the purpose of allowing the iiat spring plate I, to yield therein. Extending from the cap is a tang g3, which is provided with a locking lug g, which fits in the recess c, in the standard of the desk and prevents the cap from rotation. 'lhe friction disk I-I is concave on the side h, which bears against the protuberauce f7 on the knuckle or ball like member F, of the hinge joint. The friction disk is provided with two oppositely arranged rectangular lugs h', 7L', which lit in the notches g', g in the cap G. The notches are of sufficient depth to allow a slight lateral or sliding movement of the friction disk in the cap but they lock the disk in the cap and prevent the disk from rotation. The side h2 of the disk toward the crown of the cap is slightly convex as shown in Fig. 6. Said side h2 of the disk bears upon and is pressed against the spring I in the cap when the member F is moved. The concave side of the disk is provided with a ridge or swell h3 shown in Fig. '7. The arrangement of the ridge or swellon the concave side of the friction disk and the swell onthe hemi-spherical portion f7, is such that when the seat arm, to which the knuckle or member F is attached, nearly reaches its limits of movement in either direction the friction disk is forced laterally in the cap and bears withincreased friction against the Iiat metal spring and slows down the movemen of the seat arm. i

Each of the several parts of the ball-disk joint is provided with a circular opening L. The bolt K extends through this opening and serves to retain the several parts together. The bolt is preferably provided with a nut M, which is seated and prevented from rotation by a rectangular recess m, inthe cap G.

Having fully described my invention, what I claim, and desire to secure by Letters Patent, ism

l. In a school desk joint, the combination of 'a socket-piece secured to the desk standard and provided with a concavity in its center, a flat bearing surface surrounding the concavity, a segmental slot or recess in said bearing surface, and a rim partially surrounding the same, a pivoted or rocking member connected to the seat arm having on one side a ball like protuberauce to fit into the concavity in the socket-piece, a flat circular bearing surface, a lng thereon to engage the slot in the socket-piece, and a segmental rim to bear against the periphery of the socket piece, and on its other side a similar ball-like protuberance having a cam or swell, a cap-piece havinga fiat circular bearing surface, a projecting tang having a lug which extends into a recess in the standard and prevents the rotation of the cap, and notches in the crown, a concavo-convex friction disk having projecting lugs which extend into the notches in the crown of the cap, a projecting cam or swell on the concave side, and aspring metal plate located between the friction disk and the top of the cap, and means such as a bolt for securing all the parts together, substantially as set forth.'

2. The combination of a socket-piece having a segmental slot, a pivoted or rocking member having a ball like protuberauce to turn in said socket piece, a lug to engage in the slot, and a similar protuberauce on its other side provided with a cam or swell, a friction,

disk fitting over said protuberauce and provided withy a corresponding cam or swell, a spring bearing against said disk, a cap-piece inclosing said disk and spring, and means for securing said parts together, substantially as described.

3. The combination of a socketpiece,a pivl oted or rocking member tting in said socketpiece and having a ball like protuberauce on each of its sides, a concave friction disk fitting over one of the ball like protuberances, a spring bearing on the friction disk, a cap piece, and means for securing the parts to roo 5. In a school desk hinge or joint, the combination of a socket-piece, a pivoted or rocking memberhaving on 011e side a semispherical or ball-like protuberauce fitting a depression in the socket-piece, a similar protuberauce having a swell on the other side, a friction disk provided ou one side with a swell, a spring bearing against the other side of the disk, and a cap-piece having a crown iuclosing the friction disk and spring, and flanged rim entirely surrounding the crown andbearing against the flat surface of the rocking member, all substantially as described.

6. In a school desk joint the combination of a standard having a socket piece, a seat arm having a member to turn in said socket-piece provided with a ball like projection on each of its sides, aspring pressed friction disk, suitable swellls on the ball and friction disk for increasing the friction, a cap piece and means for securing said parts in place.

In testimony whereof I afiix my signature in presence of two witn esses.

JAMES WILLIAM FISI-IER.

Vitnesses:

A. J. Huss, M. G. SMITH.

IIO 

